27th Regiment, Illinois Infantry
The 27th regiment, Illinois Infantry was organized at Camp Butler, Illinois, August 10, 1861. At Jacksonville, Illinois It was ordered to Springfield, Illinois, August 25 and mustered out September 20, 1864. 
Companies in this Regiment with County of Origin
Men often enlisted in a company recruited in the counties where they lived though not always. After many battles, companies might be combined because so many men were killed or wounded. However if you are unsure which company your ancestor was in, try the company recruited in his county first.
The following counties of origin are taken from the Adjutant General's Report, found on the Illinois Civil War Rosters web site. Roster pages are from the same report found on the Internet Archives web site. The rosters show the men who served in each regiment, their residences, dates of enlistment and mustering out, and other remarks.
- Company A - many men from Adams County - Adams County web site - Roster, vol. 2, pages 390-392.
- Company B - many men from Scott County - Scott County web site - Roster, vol. 2, pages 392-394.
- Company C - many men from Pike County - Pike County web site - Roster, vol. 2, pages 394-396.
- Company D - many men from Jersey County and Madison County - Jersey and Madison county web sites - Roster, vol. 2, pages 397-398.
- Company E - many men from Mason County (Also known as Hutchens' Cavalry Company)- Mason County web site - Roster, vol. 2, pages 398-401.
- Company F - many men from Madison County and Macoupin County - Madison and Macoupin county web sites - Roster, vol. 2, pages 401-403.
- Company G - many men from Mercer County - Mercer County web site - Roster, vol. 2, pages 403-405.
- Company H - many men from Jackson County - Jackson County web site - Roster, vol. 2, pages 405-407.
- Company I - many men from Bureau County and Henry County - Bureau and Henry county web sites - Roster, vol. 2, pages 407-409.
- Company K - many men from Morgan County - Morgan County web site - Roster, vol. 2, pages 410-412.
- Unassigned Recruits - Roster, vol. 2, page 412.
- Civil War Soldiers and Sailors System, (accessed 30 Dec. 2010) can be searched by soldier's name or by regiment; includes regimental rosters and additional history of the regiment.
- Illinois Civil War Rosters from the Adjutant General's Report, 27th Regiment (accessed 10 May 2011) includes rosters of all the regiments and information on the different companies in each regiment.
- Illinois State Archives - Illinois Civil War Muster and Descriptive Rolls Database (accessed 14 June 2011). Search by residence, unit, regiment, company or soldier.
- National Park Service, The Civil War Soldiers and Sailors System, (accessed 10 May 2011).